With the increasing digitalization of economical, administrative and journalistic processes and processing steps, more and more digital documents are produced and used instead of conventional paper documents because of their more flexible handling. Since data, basically, can be unrestrictedly freely copied, it is often expedient to provide these data with references as to origin or originator in the form of digital watermarks. Such digital watermarks in particular are suitable for protecting and managing rights in digital data, the so-called “Digital Rights Management” (DRM).
Digital watermarks are added to digital documents and files, in order to provide a checkable reference to origin and originator transparent for third parties. For this purpose watermarks are “woven” into the data to be marked or into their binary code such that the watermark cannot be removed without possessing a digital key (at least not without data losses) and it is not easily recognizable as such in the data from outside.
In this connection it is known to transfer data, for the purpose of being marked with a watermark, from a terminal to a separate chip card, to carry out the marking there, and to transfer the marked data back to the terminal, so that the data are present on the chip card only temporarily.
It is also known to store data on so-called multimedia cards, which do not support digital watermarks, but are used in systems which support digital watermarks.
Therefore, it is the problem of the present invention to efficiently and reliably administrate the origin or authorship of the digital data on an open system.